MONROVIA, Aug 25 (Reuters) - A Liberian doctor who treated victims of an Ebola epidemic and then contracted the disease himself has died even though he was given the experimental drug ZMapp, Liberia’s information minister said on Monday.

Abraham Borbor’s death could curb optimism about the drug that mounted last week when two U.S. aid workers who caught Ebola in Liberia were declared free of the virus after receiving the same treatment at a hospital in the United States.

People in Guinea, Sierra Leone and Liberia are desperate for a cure for the contagious hemorrhagic fever that has killed at least 1,427 people since March in the deadliest outbreak the world has seen.

But Mapp Biopharmaceutical says it will take time to replenish its exhausted stocks of ZMapp and scientists say it is too early to confirm the value of the medication that has been tested on laboratory animals but not previously on humans.

The disease has reaped a grim toll on healthcare workers, often working long hours in tough conditions at low-tech facilities, often lacking adequate protective gear.

Nearly 100 have died, according to the World Health Organization, including doctor Sheik Umar Khan, who was considered a hero in his native Sierra Leone for leading the fight against Ebola.

Doctors at the Medecins Sans Frontieres (MSF) facility where he was treated agonized over the ethics of giving him ZMapp and the risk of a backlash if it was perceived to have killed him. They decided against it.

Victims suffer vomiting, diarrhoea, internal and external bleeding in the final stages of the disease, leaving their bodies coated in the virus.

Liberia, where Ebola is spreading fastest, received three doses of ZMapp on Aug. 13 and used them to treat three doctors: Borbor and Zukunis Ireland from Liberia and Aroh Cosmos Izchukwu from Nigeria.

Initially, officials said they were responding to treatment but Information Minister Lewis Brown said Borbor died on Sunday. A Spanish priest treated with ZMapp this month also died.

OUTBREAK ADVANCING

There are other drugs in the pipeline and the outbreak has added urgency to research into a disease with no cure or vaccine, but all the drugs are unproven and have yet to clear even the initial stage of clinical trials.

In one sign of potential progress, four monkeys survived Ebola after being injected with Immunovaccine Inc’s experimental vaccine, the Canadian company said on Monday, an announcement that sent its stock soaring.

West Africa’s first Ebola outbreak was detected five months ago in the forests of southeastern Guinea but it was not until Aug. 8 that the World Health Organization declared an international health emergency and promised more resources.

That delay drew criticism from some health groups, who said the U.N. health agency should have responded faster.

“It appears that the outbreak is still advancing and is advancing in many parts of the country (Sierra Leone),” David Nabarro, Ebola response coordinator for the United Nations, told a news conference in Sierra Leone.

In a bid to stop the virus, West African governments have closed borders, halted flights from affected countries, stopped international conferences and increased medical provision.

Liberia declared a curfew last week and put two neighbourhoods under quarantine.

FLIGHT BAN

Fears of contamination on flights escalated in July when a man infected with Ebola arrived at an airport in Lagos, Nigeria, and collapsed. He died and five people including health care workers who treated him have died in that country since then. Nabarro urged countries to reverse flight bans.

“The understandable decision by some countries not to want to receive aeroplanes that have touched ground in this country or in its neighbours, that understandable decision has huge operational impact ... on our ability to bring in staff and to bring in goods,” he said.

Ebola has highlighted the gap between the care afforded to Western patients and many who are treated in Africa. Liberia, for example, used a school in a run down neighbourhood of the capital as a quarantine centre and patients lay on the floor.

The family of a British volunteer nurse repatriated from Sierra Leone after contracting the virus said on Monday he was in the best place possible for treatment.

William Pooley, 29, is the first Briton to test positive for the disease. He was flown home in a specially adapted Royal Air Force cargo plane and transported to an isolation unit at the Royal Free Hospital in London.

The first recorded Ebola case took place in what is now Democratic Republic of Congo and the country declared a new Ebola outbreak in its northern Equateur province on Sunday after two of eight patients tested for Ebola came back positive.

The U.N. health agency said it had sent in protective equipment for medical staff, which is not connected to the epidemic in West Africa.

Liberia’s health ministry announced on Monday that a five-person medical team from Democratic Republic of Congo had just arrived to help in the fight against Ebola. (Additional reporting by Josephus Olu-Mammah and Umaru Fofana in Sierra Leone, Stephanie Nebehay in Geneva, Emma Farge in Dakar, Kaori Kaneko in Tokyo and Belinda Goldsmith in London; Writing by Matthew Mpoke Bigg; Editing by Robin Pomeroy)